who's right in this situation, me or my sister?

[Brian Fahy]

okay so today my mom bugged out on me because i got a 66 on an english test and she was saying how i didnt study even though i did. and so she just annoyed me so much and telling me that im not trying hard and that i won't get far in life because i got that grade. and so i write on my twitter "i can not stand my mom holy shit" and so my sister was like you're being a bitch about mom and like its mean and like how would you feel if mom wrote that about you. (and sidenote: my mom doesn't have a twitter and doesnt know my account name so she wouldn't find out) and so i was like everyone does it and you did too so don't tell me how to live my life. and now shes like dont ever ask for advice again from me. like is it me thats being the bad person or is she flipping out as well.

i understand this is long but please read it and answer it seriously.

[Wayne]

You told her to mind her own business and she said fine, we'll play it your way. Hey, you cannot have it both ways and I think this time you ought to let her will the struggle

[Ekaterina]

neither was right.
if your sister did it before then shes being a hypocrite but probably feels bad for your mom and was trying to "stand up" for her.
and it was wrong of you to write that about about your mom; even though the comment wasn't too harsh. do actually try to see how you would feel if your mom had twitter and posted up "i cannot stand my son holy ****"
its better not to trash people in public. most of the time, it makes you look bad.
im sorry about her blowing up the 66% situation. parents can be buttholes. sometimes because they care.
but i wouldn't let it bother you. as long you know you tried. we all get bad test grades every now and then.